Single lever controls for controlling throttle of one or more engines are known and widely used, and incorporate both the reversing gear mechanism and the mechanism for controlling the throttle, and hence the rpm of the one or more engines, in a single device.
The reversing gear mechanism is actuated to enable switching from the reverse gear to the forward gear through the neutral position, and vice versa, as soon as the engine throttle control mechanism sets the engine/s to minimum rpm.
In prior art single lever controls, the angular motion of the lever and hence of the support shaft of the lever throughout the entire angular travel of the lever, which is required for reversing, is converted by cams and gears and is not transmitted to the engine throttle control mechanism, so that said engine throttle control mechanism is uncoupled from the support shaft of the lever and from the lever itself.
For example, the angular motion of the lever and the support shaft of the lever may be converted into a rectilinear motion by a cam.
These configurations have the drawback that the engine throttle control mechanism does not completely uncouple from the lever for the angular reversing travel of said lever.
This situation may cause the buildup of mechanical tolerances in gears, which hinders perfect synchronization of the throttle control mechanism with the reversing gear mechanism. Such synchronization requires the engines to be kept at minimum rpm throughout the angular travel of the lever required for reversing, the engine throttle control mechanism being coupled again to the lever once said travel has been completed.
Thus, the synchronization of the reversing gear mechanism with the engine throttle control mechanism may fail, causing problems for the proper operation of the engines and the reversing gear mechanism. Those problems may lead, in the most serious cases, to damages of various degrees.